In recent years, a so-called passive type, small and inexpensive wireless IC tag having no fear that a battery is exhausted has been attached to a product at a manufacturing stage in order to execute total management of a product from manufacturing to distribution, sale and the like of the product, and to prevent the product from being lost, stolen or forged.
The passive type wireless IC tag (hereinafter, referred to as just RFID) is constituted of an IC chip, coil-like or spiral-like antenna, and a coil jumper which connects both. The IC chip has a variety of necessary data stored therein, and many types of the IC chips allow new data to be written and erased and then read from outside. A starter power source of this passive type RFID is an electromagnetic induction type (or micro wave type) RFID which has no own power source but use an electromotive force generated from electromagnetic waves (or microwaves) received from an external reader/writer (or scanner) as its power source.
Therefore, the electromagnetic wave emitted from the reader/writer (or scanner) is used not only as a carrier for transmitting data but also for an electromotive force for the passive type RFID. The carrier is modulated to a wavelength meeting the passive type RFID within the reader/writer (scanner) and received by a receiving antenna of the same RFID so as to fetch out necessary data stored in a memory of the IC chip and then, the same data is modulated to a wavelength corresponding to the reader/writer (or scanner) and transmitted from a built-in antenna as response data. Alternatively, unnecessary data out of the data stored in the memory of the IC chip can be erased according to an instruction from the reader/writer (or scanner).
A signal transmitted in response is received by the receiving antenna of the reader/writer (or scanner), and the response data is analyzed by a control unit of the reader/writer (or scanner). The response data is stored temporarily in the reader/writer (or scanner) as data stored in the passive type RFID, and then transmitted to a control device such as a personal computer. Data is read out from the memory of the passive type RFID, and a variety of security means are taken upon writing of data.
Specific examples in which this kind of passive type RFID is incorporated in a fastening product include, for example, “Pull tab of slider fastener” described in Japanese Patent Application Laid-Open No. 2002-125721 (patent document 1) and “Clothes button with leg to be sewed on” described in Japanese Patent Application Laid-Open No. 2002-42100 (patent document 2).
According to a metallic pull tab of a slide fastener described in the patent document 1, a passive type RFID IC chip sealed in a narrow glass tube and a coil antenna are embedded in a main body of the metallic pull tab. For this embedding, an embedding hole for the glass tube is formed in the main body of the pull tab, and a transmission/reception slit which extends in a longitudinal direction of the glass tube and communicates inside with outside is formed in a wall face of the embedding hole. A coil antenna is exposed at a portion of the transmission/reception slit, so that signals can be exchanged with a reader/writer (or scanner) disposed outside. After the glass tube having the passive type RFID sealed therein is inserted into the embedding hole, an opening end of the embedding hole is sealed with epoxy resin to prevent the passive type RFID from falling down.
On the other hand, the clothes button with leg to be sewed on described in the patent document 2 is constituted of a button main body having magnetic permeability and a passive type RFID mounting body. A circular recess is formed on a surface of the button main body, and a leg to be sewed on clothes is provided protrudedly and integrally on a rear face of the button main body.
The passive type RFID is integrally fixed to a center of the recess so as to be covered with epoxy resin which is a low magnetic permeability material. As to the passive type RFID, an IC chip and a coil antenna wound spirally so as to surround the IC chip are disposed in the recess. After the passive type RFID is disposed within the recess, epoxy resin is poured into the recess and left to harden to carry out sealing waterproof treatment.    Patent document 1: Japanese Patent Application Laid-Open No. 2002-125721    Patent document 2: Japanese Patent Application Laid-Open No. 2002-42100